[PATCH] D83394: [AMDGPU] Avoid splitting FLAT offsets in unsafe ways

[Jay Foad via Phabricator via llvm-commits]

foad marked an inline comment as done.
foad added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp:1705
+          // Use signed division by a power of two to truncate towards 0.
+          int64_t D = 1LL << (NumBits - 1);
+          RemainderOffset = (static_cast<int64_t>(COffsetVal) / D) * D;
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arsenm wrote:
> This limitation also only needs to be applied if AS == FLAT_ADDRESS
The only "limitation" is that we don't try to split negative offsets if the immediate offset field is unsigned, but you're saying we can do that if AS != FLAT_ADDRESS? What would that mean - that we're using a FLAT instruction but we know statically which part of the address space it is accessing??


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  https://reviews.llvm.org/D83394/new/

https://reviews.llvm.org/D83394